The Food Safety Citizens' Watch was established in April 2003 as a network
of experts to monitor developments and make proposals to the government
regarding food safety issues from the citizen's point of view.

We have conducted investigations to determine the degree of heavy metal
pollution in hair from parents and children in Japan. This kind of study
is rarely done, so we think the data is very valuable. Among the heavy
metals that are needed by the body, intake of minerals through food is
necessary to a certain degree. However, there are substances that do more
harm, such as mercury, lead and cadmium. In Japan, these are known for
the specific diseases they caused in the past, such as Minamata disease
(mercury), lead poisoning, and the Itai-itai disease (cadmium). Also, arsenic
in milk and water wells have caused health problems. Aluminum is known
to cause dialysis encephalopathy syndrome, while copper has caused the
Wilson disease. Even though they are all necessary substances, they can
cause severe symptoms and disease if the intake is high.

In this study, we looked at the concentrations of harmful heavy metals
in hair samples from 34 women (control group), 78 mothers, 49 children
(female) and 31 children (boys). We investigated the levels, and generally
we found that they were higher in the children than in their mothers.

We found that for both mercury and arsenic there was a positive correlation
between levels found in mother and child. For cadmium, lead, and aluminum,
there were significantly higher values in the children than in the mothers.
Some among the children had 10 times higher levels compared to their mothers.

When we looked at cadmium and lead levels in girls according to their age,
we found the highest levels in the 0-3 age group. The highest aluminum
levels were in boys in the 0-3 age group. As for minerals that are considered
necessary (iron, chrome, manganese and molybdenum), the levels found in
all the children are high, while zinc, magnesium and calcium levels are
low.

Except for mercury, we have no data about the correlation of concentrations
of high levels of heavy metals in hair samples compared to body samples.
This correlation has only been studied in the case of the Minamata disease.
For other heavy metals, the levels are not well understood.

From 2008, the Ministry of the Environment has started a nationwide investigation
by registering 100,000 pregnant women, to see if chemical substances such
as mercury have any influence on the growth of the children until the age
of 12. This is an unprecedented investigation.